I received this from John Sinnard and thought you might like to see the
picture also.

Jim Fayer
jimfayer@prodigy.net
Sat, 13 Nov 1999 19:49:15

Date: Sunday, November 07, 1999 3:41 PM

Every so often, just the right combination of conditions and events
occur to create an unbelievable event -- in this case an F-18 passing
through the sound barrier. Not only were the water vapor, density and
temperature just right, but there just happened to be a camera in the
vicinity to capture the moment. The F-18 is actually in transonic
flight, with normal shock waves emanating from behind the canopy and
across the wings and fuselage. The condition will last for only an
instant, and once supersonic flow exists completely around the aircraft,
sharp-angled sonic cones replace the normal shock waves. The odds of
getting a shot like this are staggering. I like it.

More Story

Through the viewfinder of his camera, Ensign John Gay could see the
fighter plane drop from the sky heading toward the port side of the
aircraft carrier Constellation. At 1,000 feet, the pilot drops the
F/A-18C Hornet to increase his speed to 750 mph, vapor flickering off
the curved surfaces of the plane. In the precise moment a cloud in the
shape of a farm-fresh egg forms around the Hornet 200 yards from the
carrier, its engines rippling the Pacific Ocean just 75 feet below, Gay
hears an explosion and snaps his camera shutter once. "I clicked the
same time I heard the boom, and I knew I had it," Gay said. What he had
was a technically meticulous depiction of the sound barrier being broken
July 7, 1999, somewhere on the Pacific between Hawaii and Japan.

Sports Illustrated, Brills Content and Life ran the photo. The photo
recently took first prize in the science and technology division in the
World Press Photo 2000 contest, which drew more than 42,000 entries
worldwide.

"All of a sudden, in the last few days, I've been getting calls from
everywhere about it again. It's kind of neat," he said, in a telephone
interview from his station in Virginia Beach, Va.

A naval veteran of 12 years, Gay, 38, manages a crew of eight assigned
to take intelligence photographs from the high-tech belly of an F-14
Tomcat, the fastest fighter in the U.S. Navy. In July, Gay had been part
of a Joint Task Force Exercise as the Constellation made its way to
Japan.

Gay selected his Nikon 90 S, one of the five 35 mm cameras he owns.
He set his 80-300 mm zoom lens on 300 mm, set his shutter speed at
1/1000 of a second with an aperture setting f F5.6. "I put it on full
manual, focus and exposure," Gay said. "I tell young photographers who
are into automatic everything, you aren't going to get that shot on
auto.

The plane is too fast. The camera can't keep up." At sea level a plane
must exceed 741 mph to break the sound barrier, or the speed at which
sound travels.

The change in pressure as the plane outruns all of the pressure and
sound waves in front of it is heard on the ground as an explosion or
sonic boom.

The pressure change condenses the water in the air as the jet passes
these waves. Altitude, wind speed, humidity, the shape and trajectory of
the plane - all of these affect the breaking of this barrier. The
slightest drag or atmospheric pull on the plane shatters the vapor oval
like fireworks as the plane passes through, he said everything on July 7
was perfect, he said. "You see this vapor flicker around the plane that
gets bigger and bigger. You get this loud boom, and it's instantaneous.
The vapor cloud is there, and then it's not there. It's the coolest
thing you have ever seen."